Refractory element for electric heaters



y May 3, 1949. F. YOKEL 2,469,287

REFRACTORY ELEMENT FOR ELECTRC HEATERS Filed oct. 10, 1945 z 'shwrs-sheet 1 O- +I l 'n l 0 H u 'l N C LD' lv l Q l l V; M 1 1 l 1 I N l l IM N l'bl`\ EN; l 51 l s :i l I 99, I l 1| |1 1m 2 I 'N i N l N Q E" 1 in Q 1| i NV i M l 1 N N 1 u E nl; g 'l i d ||i I m N L L5 u I N p N N l l x I H '`1 @l i FL( R1 l m g l :I l I (o l l t Q N w Q i |I u) l I l XD l: l Vm I I I 'f I 1 [1l |I I I l UL "0) Q l 'i FS-3. Lm. i l YQ? f l' l l i Il b u y I "QV J May 3, 1949. F. YoKEl. 2,469,287

REFRACTORY ELEMENT FOR ELECTRIC HEATERS Filed oct. 1o, 1945 3 sheets-sheet 2 1116.4. l -lvlca ZnT/en t 0T jrank Yojc e Z May 3; 1949.

F.YOKEL REFRACTORY ELEMENT FOR ELECTRIC HEATERS t Filed Oct. l0, 1945.

s sheets-sheet 5 Patented May 3, 1949 UNITED STATES PATENT OFFICE REFRACTORY ELEMENT FOR ELECTRIC HEATERS 12 Claims. 1

My invention relates to electrical stoves, heaters, and the like, which contain electrical resistors or filaments that are mounted in refractory supports, sometimes called refractory elements. In service the resistors are electrically energized, and when so energized they generate heat which is radiated and conducted to the atmosphere, or other gaseous, liquid, or solid substance to be heated.

More particularly, the invention relates to the refractory elements for the resistors, and the nvention consists in certain new and useful improvements in the mechanical design and construction thereof, whereby, without sacrifice of economy in manufacture, the refractory elements provide for improved heat delivery, and provide protection against the overheating of the refractory body of the support.

The invention will be understood upon reference to the accompanying drawings, in which:

Fig. 1 is a view in front elevation of a refractory element which in exemplary way embodies the invention;

Fig. 2 is a view in side elevation of the element;

Fig. 3 is a view in plan of an electrical resistor of the sort that may be carried by the element in service;

Fig. 4 is a view in end elevation of the element;

Fig. 5 is a view in cross section of the element, as seen on the plane V-V of Fig. 1;

Fig. 6 is a fragmentary sectional view of the element, as seen on the plane VI-VI of Fig. l, and showing additionally a section of the body of the stove, or the like, which mounts the element and its resistor for service;

Fig. 7 is a fragmentary view, showing in front elevation a modied form of the element oi the invention;

Fig. 8 is a view in cross section of the modified form of the element;

Fig. 9 is a fragmentary view in side elevation of another modied form of the element of the invention, in which the element body is constructed of a plurality of preformed sections;

Fig. 10 is a view in cross section, on the plane X-X of Fig. 9; and

Fig. 11 is a view in perspective of one of the preformed sections of which the modified element body is constructed.

The article oi the invention consists, as has been already mentioned, in an improved element for resistors or electrical heating filaments. The reference numeral 2 indicates a typical element of the invention in the attached drawings. The body is essentially formed of a refractory material which is a non-conductor of electricity. The art is familiar with clays or ceramic mixes of which the element may be integrally molded, dried, and then brought to vitreous state by firing. So far as the composition of the refractory material, of which the element 2 is formed, and the method of its production are concerned, it will suice to remark that the prior art is Well versed on such matters, wherefore further detail herein is needless to a full understanding of the invention. The invention consists in the particularly effective design and construction of the element per se.

The refractory body of the element 2 comprises an elongate base portion 3, including two laterally spaced, parallel bores 4 which in this case extend throughout the length of the body, to receive each a helically coiled resistor of conventional metallic composition. Preferably, but not necessarily, the exposed wall of each bore includes two longitudinal lines of windows 40, of which more will be said later.

A typical resistor is shown in Fig. 3, including two reaches 5 of coiled wire, interconnected at one end by means of a section 6 of straight wire. The resistor will be seen to be in the shape of the letter U laid on its side, with the two legs of the U formed by the coiled reaches 5 of the Wire, and the base of the U formed by the straight section 6. The entire resistor may thus be constituted of a continuous length of wire, coiled in the reaches 5 and straight in the reach or section E.

The body of the element 2 at one end includes a channel 1 that extends laterally between the ends of the bores 4, and it will be perceived that the U shaped resistor may be assembled in the element, with one coiled reach of wire 5 in each bore 4 and the straight section 6 inset in the channel 'I at one end of the element body. At the opposite end, the element body is provided with four holes 8, by means of which any of the known types of metal clamps (not shown) may be bolted or otherwise secured to the body, to receive in electrical union both the terminals 9 at the distal ends of the coils 5 and the terminals of the conductor wires (not shown) that deliver electrical current through the component parts of the resistor in series.

The body of the element includes two holes I 0, through which the bolts I I, as indicated in Fig. 6, of the supporting frame or panel I2 of a stove or the like may be passed and security effected, as by means of nuts I3. The body of the refractory element includes a socket I4 at the inner end of each hole I0 to receive the nut I5 3 which may be provided rigidly to unite or look each bolt II to the frame or panel I2. As thus mounted on the frame or panel of a stove, any desired number of elements 2 and their resistors may be arranged side by side, and such elementresistor units may extend horizontally or vertically, depending upon the size and the structural design of the stove. And, of course, the resistors of the severalvunits may be-electrically connected, either in series or in parallel, `to the source of electrical power.

Turning noW to the features in which the invention is more particularly centered, it is to be understood that the structure of vthe refractory support 2 is so constituted that heat radiation may be obtained with maximum overall heating eiciency. This heat liberation is effected from the extended areas/ofthe finned or Webbed refractory body of the element heated,

under the influence of radiation, conduction and convection, by the resistor portions within the bores 4.

It will be observed that .the body of Vthe refractory element is so particularly fashioned as to provide maximum radiatingsurface per unitof mass of the refractorybody, itbeing understood that the limitationsimposed by the low structural strength .of .the vitreous composition -of the refractory body `resultin certain restrictions in thearea of radiation that may beobtained per unit of massof the body. With these circumstances in mind, .it .is to .be noted that .the mechanical for-m of the refractory .element .2 is exceedingly effective.

At each end ofthe element 2 and at spaced intervals longitudinally thereof web-like portions I6 are formed integrallywiththe refractory-body of the element. These outstanding .web portions IBeXtend circumferentially of .thebores 4, and the circumferential vweb portions `ofone bore are in this case ,paired and united, as one, with the Web portions I6 outstanding .from-thewall-of the otherfbore. These YWeb porticns areninel in number in the structureherein shown, and-they are effective .to Zprovide `vvithin .the exposed face vof the supporteight recessesor pocketsI'I that extend transverselyof theA element bodyand` of the bores l formed therein. .The lnumberof Web portions may be varied as may beideemed advisable in particularinstances,.and the number of recesses will be-correspondingly modified lin number.

Advantageously, the windows 40 open from the bores into these transverserecesses, and from these Windows 'lines .or.channels Iof direct Yheat radiation are vestablished by the -Web por-tions, While such Aweb portions, themselves becoming heated, provide extendedf-areasfor indirect sur-- face radiation of heattto the-ambientatmosphere.

The structure isfurther.- advantageously refined by thegprovisionszof .longitudinal Webportions I8V that stand onthe axial planeaof each bore that extends 4between the tWo lines of windows v'MI opening `from -the bore. Additionally, another longitudinallyextending.web portion, 'I 9, projectsy radially from each boreaand .each'web portion I8 i will be'seen to be disposed,;relativelyto theaxis of the associate bore, at an tangle .of ninety .degrees from the plane of `the Web portion I8. These longitudinal Web-.portions I8 and I9 rintersect and integrally interconnect the circumferential Web .fportions ZIS, `notonly structurally reinforcing the Whole, but also dividingvthetransverse heat-'radiating recesses or pockets IT into a plurality of `'compartments that aredirected radially outward from the Windows MI, Thus, the body portion of the element which is exposed in the face of the stove, or the like, in which service assembly is made, is divided by circumferential web portions I6 into a succession of transverse recesses, which in turn are divided into radial compartments by means of the web portions I8 and I9. Maximum heat radiation is iby -such.structure obtained, `With the valuable concomitant effect that the refractory body of the support is protected from harmful overheating.

.Radial compartments are provided between .each longitudinalweb portion I9 and the central orbasal body portion of the element. Since these .latter compartments will not ordinarily be positioned for unobstructed heat-radiation when the resistor-support unit is assembled in a stove, windows .'49 Will not ordinarily open from the bores 4 into such compartments. However, these latter compartments 1have a kdefinite .beneficial effect, in -that they ,promote the dissipation of heat that would otherwise tendto over-heatand injure Athe refractory .bodyofthe. support.

Figs. 7 andSillustrate a modincation,.in which therefractory support is constructed withk ay single.r

bore V4a. .The circumferential Web portions IBa and longitudinal vweb I8a form the counterparts of the web portions I6 and IB of .the-structure first described, Whilethe basal portion 3a.of the modified support is ,laterally extended to receive the holes vIllafor the.mounting bolts onthe stove frame,.and holesa ffor connector. clamps at each end of the body. The .laterally .extending :portions `of the base r3a Yalso Vvprovide .the functional counterparts ofthe web portions I9.

While the modifiedstructure.ofFigsfZ and. 8,. a5 Well as the structure ofFigs. .1 .to 6, is Shown tobe fashioned as a molded monolithic article, it ,will .be perceived by thev artisan that thebodies of the supports maybe .made insectionsadapted to be assembled to form kthe completed article, of the same utility as though made in one `piece as herein '.described.

In exemplication of the various modifiedv con-l structions in .which,therefractoryelementl of the invention may .beproduced I show .in/Figures 9 to ll that the body of the element may consist of a vplurality of preformed .refractorysections one of which is .shown .in .perspective .in .Figure 11, comprising a disk orcircumferential web portion Ib, including acentral `perforation 4b, and vanes or longitudinal .web portions I8b-and I9b. These vanes `orlongitudinal web portions are. eachk perforatedas at lv20, on aline parallelingl the axis of the perforation 4b.and.by means-of such perforations a 4series of the ypreformed -vsections maybe strung upon three yvviresor `rods 2 I, and such rods anchored in refractory'bracket members 3b at reachfendof -.the series,.as indicated fragmentarily in Figure 9. rllhe bracket.

bers of appropriate contour. It is 'significant to note that, as thus assembled on three rods 2|, each series or line of preformed sections affords a structure which in general is the like of that first described herein. The vanes [8b and |911, respectively, meet in end-to-end abutment, forming in the assembly the counterparts oi' the webs I8 and i9 first described, and the aligned perforations 4b at the centers of the circumferential web portions lb form, in conjunction with the radial inner edges of the longitudinal web portions |8b and I9b, the bore which receives a coiled resistor wire. The spaces between the inner edges of the web portions Ib and |917 provide windows 40h in the comparted recesses formed by and between the circumferential and longitudinal web portions lsb and lb, leb.

In the case of the double-bore structure shown in Figures 9 and 10, it will be perceived that the straight section of wire (cf. 6, Fig. 3) that interconnects the two coiled reaches 5 of the resistor may extend through openings 40h between the webs I8b and lilla` at one end of the assembly, and thereby avoid the necessity of forming a channel (such as the channel 1 of Fig. 4) in the body of the adjacent bracket 3b.

Within the terms of the appended claims it will be understood that various other modifications of the structure of the invention are held in contemplation without departing from the spirit of the invention.

I claim:

1. An article of the class described comprising a refractory body including a bore for an electrical heating element, said body having a plurality of n portions extending circumferentially of the wall of said bore and arranged in spaced-apart relation longitudinally thereof to provide a plurality of heat-radiation-directing recesses extending transversely of said bore, and a web extending longitudinally between the successive circumferential portions and dividing said recesses into radial compartments.

2. An article of the class described comprising a refractory body including a bore for an electrical heating element, said body having a plurality of fin portions extending circumferentially of the Wall of said bore and arranged in spaced-apart relation longitudinally thereof to provide a plurality of heat-radiation-directing pockets extending transversely of and open radially outward from the wall of said bore, and plurality of webs spaced apart on the circumference of said bore and interconnecting the circumferential portions first named and dividing said pockets into compartments.

3. An article of the class described comprising a refractory body including two elongate substantially parallel bores, said body provided with outstanding web portions extending circumferentially of each bore and spaced apart longitudinally of the bores and providing heat-radiation-directing pockets that extend transversely of said body and the bores therein and open radially outward from the walls of said bores, and a longitudinally extending web associated with each bore in said body and arranged to interconnect said transverse web portions to divide said pockets into compartments.

4. An article of the class described comprising a refractory body including two elongate substantially parallel bores, said body provided with outstanding web portions extending circumferentially of each bore and spaced apart longitudinally of the bores and providing heat-radiation-directing pockets that extend transversely of said body and the bores therein and open radially outward from the walls of said bores, and a plurality of longitudinal webs associated with each bore in said body, the longitudinal webs associated with each bore being spaced apart circumferentially of the bore to compart said transverse pockets.

5. An article of the class described comprising a refractory body including a windowed bore for an electrical heating element, said body having a plurality of portions extending circumferentially of the wall of said bore and arranged in spaced-apart relation longitudinally thereof to provide a plurality of transverse heat-radiating pockets into which the windows of said bore open, and a web extending longitudinally between the successive circumferential portions and dividing said pockets into compartments that open radially outward from the wall ci said bore.

6. An article of the class described comprising a refractory body including a windowed bore for an electrical heating element, said body having a plurality of portions extending circumferentially of the wall of said bore and arranged in spaced-apart relation longitudinally thereof to provide a plurality of transverse heat-radiating pockets into which the windows of said bore open, and plurality of webs spaced apart on the circumference of said bore and interconnecting the circumferential portions first named and dividing said pockets into compartments that open radially outward from the wall of said bore.

7. An article of the class described comprising a refractory body including two elongate substantially ,parallel windowed bores, said body provided with outstanding web portions extending circumferentially of each bore and spaced apart longitudinally of the bores and providing heat-radiating pockets that extend transversely of said body and the bores therein that open radially outward from the walls of said bores, with the windows of the bores opening into said pockets.

8. An article of the class described comprising a refractory body including two elongate substantially parallel windowed bores, said body provided With outstanding web portions extending circumferentially of each bore and spaced apart longitudinally of the bores and providing heatradiating pockets that extend transversely of said body and the bores therein and open radially outward from the walls of said bores, with the windows of the bores opening into said pockets, and a `longitudinally extending web associated with each bore in said body and arranged to interconnect said transverse web portions to divide said pockets into compartments.

9. An article of the class described comprising a refractory body including two elongate substantially parallel windowed bores, said body provided with outstanding web portions extending circumferentially of each bore and spaced apart longitudinally of the bores and providing heat-radiating pockets that extend transversely of said body and the bores therein and open radially outward from the walls of said bores, with the windows of the bores opening into said pockets, and a plurality of longitudinal webs associated with each bore in said body, the longitudinal webs associated with each bore being spaced apart circumferentially of the bore to compart said transverse pockets,

10. An article of the classdescribed 'comprising a refractory body having a longitudinal bore for the reception of an electric heating element and including a plurality ofoutstanding spaced transverse web portions and at least'one longi-v tudinal web portion providingon opposite sides of said bore a plurality of heat-radiating coinpartments, said longitudinal web portion extending with its base contiguous to said bore, and the wall of said bore on opposite sidesoi the base of the longitudinal web lportion vbeing' windowed to provide near the bottoms for" the compartments on opposite sides of the latter web portion open cominunicationwith said'bore.

11. An article of the classdesoribed comprising a refractory body including two elongate substantially parallel bores for the 4reception of electric heating eleinentsysaidbody being provided with outstanding web portions extending transversely of each bore and spaced apart longitudinal of the bores to provide a pluraiityfof heat-radiating pockets that extend transversely of said body and the bores therein, and a partition web portion extending longitudinally of each of said bores and between the successive web portions first mentioned to divide said pockets into compartments, the walls of said'borcbeing windowedon opposite sides of said partiton'webs adjacent to the points where said partition webs join said refractory body to provide open cornmunicationbetween the bores and said compartments.

12. An article of theclass described comprising a refractory body including a plurality of elongate substantially parallel bores forthe vreception of 'electric heating elements, -said body being provided with outstanding web Aportions extending transversely of said'bores andspaced apart longitudinally thereof to provide a plurality of heat-radiating pockets that extend transverselyof said body and the'bores therein, partition web portions extending longitudinally of said bores'severally and between thesucoessive web portions rst mentioned to divide-'said pockets into-compartments, the Walls'of said bores 'being windowed on opposite sides of the partition webs severally associated therewithand adjacent to the points where Vsaid partition webs vjoin said refractory body to provide open communication between the bores and said compartments.

FRANK YOKEL.

REFERENCES `CITED The following references are-of Arecord inthe le of this patent:

UNITED STATES PATENTS Number Name Date 1,475,152 Abbott Nov. 27, 1923 1,555,334 Vaughan Sept. 29, 1925 1,614,321 Smalley Jan. 1l, 1927 1,617,916v Kercher et al Feb. 15, 1927 1,662,771 Whittingharn Mar. 13, -1928 1,935,163 Parsons Nov. 14, 1933 1,997,146 Hynes Apr.'9, v1935 

